Abstract: Tanzania has an estimated HIV seroprevalence of 4.7%, and 1,400,000 persons living with HIV infection. It faces significant obstacles to optimal care and prevention services including a lack of HIV-related knowledge, co-morbidities of mental illness and substance abuse, poverty, rural residence, limited health care infrastructure, and inadequate numbers of health care personnel. Tanzanian leadership and the PEPFAR Country Operating Plan have prioritized the uptake of testing services, optimizing adherence to antiretroviral therapy (ART), promoting diligent monitoring of ART with viral load testing, and addressing co-morbidities of mental illness and substance abuse. In this context, the importance of developing in-country research expertise in sociobehavioral and implementation sciences is extraordinary. The Duke University Global Health Institute (DGHI) and Kilimanjaro Christian Medical Center (KCMC)/Kilimanjaro Christian Medical University College (KCMU Co) have partnered to develop such expertise. They have a robust portfolio of research supported by six different NIH Institutes. Development of research expertise has been a priority, and has been supported by four D43 awards and the Medical Education Partnership Initiative. In our current D43 funding cycle, the HIV and Sociobehavioral Sciences Research Training Program has supported the trainings of three PhD's, one Master's of Medicine (MMed) in Psychiatry, three Master's in Public Health, and three short-term trainees to build research capacity. Many of these trainings have occurred in a South-South relationship between the University of Cape Town (UCT) and KCMC/KCMU Co. In this competitive renewal application, we propose trainings to further expand and solidify these initial efforts. Candidates will pursue PhD trainings in implementation science (University of North Carolina) and Psychology at (UCT), MMed in Psychiatry (UCT), MPH (UCT), and short-term trainings. Upon completion, these scientists will join those from the current D43 training cycle to form a talented team with a breadth of expertise to perform rigorous sociobehavioral and implementation science research. Together they will have access to a limited pool of pilot research funds through this proposal to further their pathway to independence. They will receive strong institutional support from the research environment and culture of KCMC/KCMU College, who have also agreed to create Departments of Sociobehavioral Sciences and Sociobehavioral Medicine to host the scientists upon return to Moshi.